Dual Functions of Performance Improvement and Lead Leakage Mitigation of Perovskite Solar Cells Enabled by Phenylbenzimidazole Sulfonic Acid.

With the continuous improvement of performance of lead-based perovskite solar cells (PSCs), the potential harm of water-soluble lead ion (Pb2+ ) to environment and public health is emerging as a major obstacle to their commercialization. Herein, an amphoteric phenylbenzimidazole sulfonic acid (PBSA) that is almost insoluble in water is added to the perovskite precursor to simultaneously regulate crystallization growth, passivate defects, and mitigate lead leakage of high-performance PSCs. Through systematic research, it is found that PBSA can not only regulate the crystallization of perovskite grains to form the film, but also passivate the defects of annealed films mainly due to the strong interaction between the functional groups in PBSA and Pb2+ , which greatly improves the crystallinity and stability of perovskite films. Consequently, the highest power conversion efficiency of 23.27% is achieved in 0.09 cm2 devices and 15.31% is obtained for large-area modules with an aperture area of 19.32 cm2 , along with negligible hysteresis and improved stability. Moreover, the leakage of lead ions from unpackaged devices is effectively prevented owing to the strong coupling between PBSA molecules and water-soluble Pb2+ to form insoluble complexes in water, which is of great significance to promote the application of optoelectronic devices based on lead-based perovskite materials.

Stimuli-Responsive Properties of Aggregation-Induced-Emission Compounds Containing a 9,10-Distyrylanthracene Moiety.

Two 9,10-distyrylanthracene-based luminophores exhibiting aggregation-induced emission and stimuli-responsive properties were synthesized. Seven- or five-color luminescence switching based on a single organic molecule was achieved for the first time. These phase transitions can be induced by physical stimuli such as grinding by mortar and pestle, heating, and exposure to the vapors of organic solvents. Moreover, a strategy for the design of new mechanoresponsive materials with π-conjugated luminophores is proposed.

Development of a Neutralizing Monoclonal Antibody Against Porcine Epidemic Diarrhea Virus S1 Protein.

The truncated spike protein (S1, 390-789aa) of porcine epidemic diarrhea virus was expressed as a recombinant protein in Baculorvirus expression system. Female BALB/c mice were immunized with the purified recombinant S1 (rS1) protein and two monoclonal antibodies, designated 8A3A10 and 12C4G12, were generated by hybridoma technique. The two monoclonal antibodies specifically reacted with PEDV rS1 protein, as proven by Western blot and indirect immunofluorescence assay. 8A3A10 monoclonal antibody showed a neutralizing activity to PEDV, as demonstrated in the results of fluorescent focus neutralization assay. These two newly established monoclonal antibodies may work as a useful tool to study the pathogenic mechanisms of PED virus and to develop diagnostic reagents.

Facile synthesis of porous Bi2WO6 nanosheets with high photocatalytic performance.

Compared with the well-known three-dimensional Bi2WO6 nanosheet-assembled nanostructures, the free-standing two-dimensional porous Bi2WO6 nanosheets have seldom been reported. The possible reason is that Bi2WO6 nanosheets with a high surface-to-volume ratio usually tend to self-assemble or aggregate to form microspheres to reduce their surface energy. To prevent their aggregation, in this study, a new and facile self-assembled route, which includes the in situ ion-exchange reaction of Na2WO4 solution with the Bi(NO3)3 solid powder and the following high-temperature calcination, has been successfully developed to prepare the free-standing porous Bi2WO6 nanosheets. The ion-exchange reaction between the Bi(NO3)3 solid and Na2WO4 solution can in situ produce amorphous Bi2WO6 nanosheets, while the high-temperature calcination (500 °C) causes the formation of homogeneously porous structures in individual nanosheets during their phase transformation from amorphous to crystalline. The resultant porous nanosheets are composed of one-layer Bi2WO6 nanoparticles with a size of 30-50 nm, and there is a strong coupling interface among these nanoparticles. Photocatalytic experimental results suggest that the resultant porous Pt/Bi2WO6 nanosheets show a high photocatalytic performance for the decomposition of phenol solution. Considering their facile preparation, the present synthetic route may provide new insights for the design and fabrication of other nanostructured materials with various potential applications.

The dynamics of Chinese variant porcine epidemic diarrhea virus production in Vero cells and intestines of 2-day old piglets.

A severe porcine epidemic diarrhea (PED) epizootic has been affecting pigs of all ages that are characterized by high mortality among suckling piglets in China since late 2010, causing significant economic losses. Obtaining a current-circulating PEDV variant isolate that can grow efficiently in cell culture is prerequisite for the development of efficient vaccines. In this study, PEDV strain HN1303 was isolated successfully on Vero cells with supplemental trypsin, and the isolate has been serially propagated in cell culture for over 95 passages. The infectious titers of the virus during the first 10 passages ranged from 10(2.6) to 10(5.8) 50% tissue culture infective doses (TCID50)/ml, and the titers of 20-95 passages ranged from 10(6.2) to 10(8.0)TCID50/ml. The growth curve of Vero cell-adapted HN1303 in cell culture was determined, and dynamics of virus production was confirmed by immunoperoxidase monolayer assay (IPMA). Sequence and phylogenetic analysis based on spike gene indicate that the HN1303 strain belongs to genotype IIa. In addition, the fourth passage cell-culture HN1303 was subjected to 2-day old piglets. All piglets orally inoculated developed severe watery diarrhea and vomiting within 24 hours post-inoculation (hpi) and died within 72 hpi. The results of animal experiments reveal that this strain is highly pathogenic to 2-day old piglets.

Construction of a triple gene-deleted Chinese Pseudorabies virus variant and its efficacy study as a vaccine candidate on suckling piglets.

New-emerging variants of Pseudorabies virus (PRV) compromise the protection provided by current vaccines and cause the death of all ages of vaccinated pigs since 2011. New vaccines based on current circulating PRV strain are needed to control the spread of disease since the variants are antigenically different from classical strains of virus. In this study, a TK/gE/gI triple gene-deleted PRV derived from current circulating field isolate was generated by using bacterial artificial chromosome techniques, and the rescued virus showed similar growth properties in vitro to its parent strain but reduced plaque size. To evaluate it as vaccine candidate, 9 day-old pigs were vaccinated and challenged with a virulent PRV variant. The results showed that vaccination can generate high level of protective gB-specific antibodies after vaccination and provide complete protection to the viral challenge. By contrast, the unvaccinated piglets all died within 6 days after viral challenge. Therefore, the TK/gE/gI triple gene-deleted PRV could be a promising vaccine candidate to control the wide spreading of PR variants in China.